Hydrochloric Acid → 1H-Indazole-3,5-dicarboxylic acid 5-methyl ester

HRID 902179Notes

Reaction equation

HRID 902179 reaction equation
[CH3:1][O:2][C:3]([C:5]1[CH:6]=[C:7]2[C:11](=[CH:12][CH:13]=1)[NH:10][N:9]=[C:8]2[CH:14]=[O:15])=[O:4].[O-:16]Cl=O.[Na+].OO.Cl>C(#N)C.CN(C=O)C.O>[CH3:1][O:2][C:3]([C:5]1[CH:6]=[C:7]2[C:11](=[CH:12][CH:13]=1)[NH:10][N:9]=[C:8]2[C:14]([OH:16])=[O:15])=[O:4]

Participants

8

Reactant 4

HCID 313Hydrochloric AcidHCID 784Hydrogen PeroxideHCID 23668197Sodium ChloriteHCID 178497393HCID 178497393, compound

Product 1

HCID 690376921H-Indazole-3,5-dicarboxylic acid 5-methyl esterYield 42.7%

Reagents, catalysts & solvents 3

HCID 962WaterSolvent2×HCID 6228DimethylformamideSolventHCID 6342AcetonitrileSolvent

Procedure

To a solution of 5 g 3-Formyl-1H-indazole-5-carboxylic acid methyl ester in 100 mL acetonitrile and 8 mL DMF a solution of 4.4 g NaH2PO4 in 90 mL water was added dropwise at RT within 1 h. Then a solution of 4.2 g NaClO2 (80%) in 90 mL water followed by 5.3 mL H2O2 (30%) was added dropwise at 0° C. After stirring for 16 h at RT the reaction mixture was cooled to 0° C. followed by addition of 180 mL half-concentrated aqueous hydrochloric acid. The precipitated product was collected by filtration to yield 2.3 g pure product. The filtrate was extracted with ethyl acetate (3×150 mL), the combined organic layers were dried over MgSO4. After removal of the solvent under reduced pressure further 3.42 g of product were obtained. The combined product fractions were used without further purification. Yield: 5.7 g.

Workup

  1. additionwas added dropwise at 0° C
  2. temperaturewas cooled to 0° C.
  3. filtrationThe precipitated product was collected by filtration

Sources & evidence

ORD record
ord-baa7a16fc75b4fef8e650f1c08e53d2e
Source dataset
uspto-grants-2008_04
Patent number
US07365088B2

Reaction notes

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